Actuated parts, grippers, and clamps are known. Typically, such clamps use pneumatic actuation to translate linear motion into rotational motion through a series of cams or links coupled to both a linearly traveling piston rod and a rotating jaw arm. Such clamps can provide a substantial gripping force, but sometimes that force does not become substantial until the final moments of the stroke. Often this can be the last thousands of an inch of a stroke. Vane clamps, in contrast, are actuated by fluid pressure engaging a vane, thereby rotating the same which, in turn, rotates a coupled jaw arm. This produces a more powerful force across a greater range of the stroke. This is useful when using tips that require sufficient torque at a position on the stroke that is not the final thousandth of an inch. For example, compliant tips having a variable gripping surface to hold a variably-shaped workpiece, the torque required needs to be substantial, possibly as much as a half inch above the end of the stroke, in some cases. This allows the first contact between the compliant tip and the workpiece to receive sufficient torque.
Typical vane clamps, however, may lose gripping power when the fluid supply is lost. Such clamps cannot lock or hold the gripper arms in place unless constant force is applied to the vane. Without power to the vane, the jaw arm will be able to move freely. This, obviously, can have a detrimental impact on certain manufacturing-line applications, when a gripping force is desired under loss-of-power conditions. It would, thus, be beneficial to provide an improved vane clamp that addresses at least one or more of these issues.
Accordingly, an illustrative embodiment of the present disclosure provides a clamp assembly which comprises a body, a power supply, a vane, a jaw arm and a stop. The power supply is coupled to the body, and the vane located in the body. The power supply pivots the vane about an axis between first and second positions. The jaw arm is coupled to and movable with the vane. The stop limits the movement of the jaw arm during a loss of power to the vane.
The above and other illustrative embodiments may also comprise: the stop further comprising a clutch assembly that prevents movement of the jaw arm during loss of power from the power supply; a cam member that engages a key attached to the vane; the jaw arm being engagable with the cam member; the vane moving the cam member that moves the jaw arm; at least one stop member located adjacent the key and cam member wherein the stop member limits movement of the cam member when power is lost; the stop member being a dowel; the cam member having at least one recess disposed therein configured to receive the dowel; the power supply moving the vane which moves the key which engages the dowel, wherein the recess receives the dowel to allow movement of the jaw arm; a shaft being engagable with the cam member and the jaw arm such that movement of the cam moves the shaft which pivots the jaw arm; the shaft defining the axis, and being disposed through but not engaging the vane; and the shaft being engagable with a member that rotates the shaft to move the jaw arm when power is lost.
Another illustrative embodiment of the present disclosure provides a clamp assembly which comprises a power supply, a jaw arm, a shaft, a rotating body and at least one stop member. The shaft is attached to the jaw arm. The rotating body is engagable with the shaft and the power supply to pivot the jaw arm about an axis between open and closed positions. The at least one stop member is engagable with the rotating body to limit movement of the jaw arm during a loss of the power supply.
The above and other illustrative embodiments may also comprise: both the shaft and the rotating body comprising a plurality of teeth disposed thereon such that as the power supply moves the rotating body the teeth on the rotating body engages the teeth on the shaft to rotate the shaft which moves the jaw arm; a manual override that engages the shaft to move the jaw arm during loss of the power supply; and at least one stop member engagable with the rotating body to selectively prevent movement of the jaw arm during the loss of the power supply.
Another illustrative embodiment of the present disclosure provides a clamp comprising a pivoting means that is movable about an axis in response to a power supply; a jaw arm coupled to and movable with the pivoting means; and a means for limiting movement of the jaw arm when the power supply to the pivoting means is lost.
Additional features and advantages of the clamp will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrated embodiment exemplifying the best mode of carrying out the clamp as presently perceived.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates embodiments of the clamp, and such exemplification is not to be construed as limiting the scope of the clamp in any manner.